Cabling records are used extensively to document the physical locations of cabling connections in environments in which it is important to be able to identify such locations accurately. For example, cabling records are often used to map the cabling connections in rooms or buildings that house telecommunications equipment such as, but not limited to, telephony switching equipment. The exact format of cabling records varies from carrier to carrier. A typical cabling record may be indexed by a circuit identifier, which represents an end-to-end high-level identifier. The cabling record lists the physical location of the termination points at either end of the cable (for example using a grid-based identifier), equipment information associated with equipment at each end of the cable, for example ‘port 57’ on ‘switch 2’, and routing information, for example which trays the cable is run in and the like. In the event of a connection failure, for example, it is important to be able to determine the physical location of the associated connection so that it can be inspected as quickly as possible. Accurate knowledge of the physical location of such connections is also important for less time-critical work such as upgrades or maintenance.
Cabling records are usually updated manually in that an engineer has to record changes in the physical location of connections in a cabling record, which often leads to inaccuracies as a result of human error, particularly where large numbers of cables are being moved. Cabling record errors and/or omissions can have serious consequences if the physical location of a given connection cannot accurately be determined, for example in the event of a failure of the connection. In some situations, this may result in loss of service for end users.
When looking to upgrade from existing, legacy telephony equipment, which can occupy many tens of equipment bays, to newer, replacement telephony equipment, questions arise as to how to migrate the old telephony equipment to the new telephony equipment; both in terms of migrating carriers from the old telephony equipment to the new telephony equipment and in terms of reducing the risk of cabling record errors and/or omissions when migrating the carriers.
In some cases, the new telephony equipment has to be run in parallel with the old telephony equipment and the circuits migrated over one at a time by rerouting the individual physical carriers and updating the telephony equipment configuration so that the rest of the network knows that the circuits have been moved to the new switch. This involves a number of expensive and time-consuming steps. Moving the large number of carriers involves much skilful and time-consuming rewiring, with great potential for error. Updating all of the per-carrier wiring records is also time-consuming and error prone. Furthermore, to allow both the new and old telephony equipment to run in parallel during the migration, the rest of the network needs to be reconfigured to see both the new and old telephony equipment, potentially with extra signalling links and the like.
In other cases, the carriers are already routed through a fully flexible transport system with the ability to route carriers to a number of destinations on the basis of a simple change to soft configuration and enough spare capacity to connect to both the replacement telephony equipment as well as the legacy telephony equipment. In that case, new links can be run from the transport system to the new telephony equipment during a preparatory phase, with the old telephony equipment still active and carrying all of the live traffic. Just before the switchover, configuration is exported from the old telephony equipment and is migrated into the new telephony equipment. Then, at some point during a maintenance window, the transport system can be used to cut all of the traffic from the old telephony equipment to the new telephony equipment. The use of this sudden cut is important as it avoids the need for the old and new telephony equipment both to be visible to the rest of the network. However, spare transport capacity is often not available and even when it is, the wiring record updates required for every carrier carries a heavy cost.
It would therefore be desirable to provide improvements in migrating telephony equipment, particularly but not exclusively, which reduce the risk of inaccuracies in updates to cabling records following telephony equipment migration.